Stairway construction



Feb. 28, 1928.

1.. w. NORBERG STAIRWAY CONSTRUCTION Filed July 5. 1926 2 Sheets-Sheet l Feb. 28, 1928.

1,660,392 1.. w. NORBERG STAIRWAY CONSTRUCTION Filed July s. 1926 2 Sheets-$119M 2 I I I I'll l I I'll yiiill Intent or x .6m UNITED STATES PArENrorFic-e.

LUnw IG w. nonsense, or BUFFALO, nnwyonx.

sw mmer cons'rnuorion.

Application filed July 3,

This invention relates to a stair construction and more particularly to metal stairbuildings, etc.

ways such as are used in factories, public One of the objects of this invention is to provide such a stairway which is strong'and durable, and is easilyand quickly assembled without requiring'the use of special skill or tools. i

A further object is to'provide such a stairway construction I in which the parts, of which the stair is composed, adaptthem selves to their proper positions relative to each other, and in which the parts can have a considerable'margin of inaccuracy without impairing thestrength or appearance of the stairs.

A still further object is to provide such astair construction which can be manufactured, and erected at low cost. In the accompanying drawings Figure 1 is a horizontal sectional View of the preferred construction of my stairway,

the same being takenonline 1-1, Fig.2., Figure 2 1s a Vertical longitudinal SECCIOII.

taken on line 22, Fig. 1. Figure 3 is a vertical transverse section of the sa'meft'aken on line 3 3, Fig. 2.- Figure 4 is an enlarged longitudinal section showing one of the ar cuate fastenlng bolts. Flgure 5' is an enlarged transverse section of the same taken on line 55, Fig. 4. Figu'reGis an enlarged fragmentarylongitudinal section showing the preferred form of nosing, Figure 7' 1s a view similar to Fig. 1, and showing a mothlied form of my invention, the cement" filler being-removed. FigureS is a've rticallongitudinal section of the modifiedfform of stair construction shown in Fig. Figure 9 is a vertical transversesection taken online 99, Fig. 8. Figure 10 is an enlarged fragmentary longitudinal section showing one of the curved fastenings used with a short section of an abutment bar. Figure 11 is a section on line 1111, Fig. 10. Figure 12is a fragmentary longitudinal section of'aform of nosing employed in connection with the modifiedformof my invention; Figure 1.3 is a similar sectional view showing another formof nosing and tread. Figure 14 shows the manner in which my inventionmay be used in connection with. an" all metal stairy:

Similar reference numerals refer to similar parts in each of the several views.

Referring to the preferred form of myv in:

rigid.

1926. Serial No. 120,435.

vent ion shown in Figs. 16, the steps or stairs are supported by the usual inclined stringers 1a, which are made" ofjmetal and are supported at their upper-and lowercnds m any well known and approved manner.

each other, and abut at their oppositeends" against the inner flat faces of the stringers 14c. The meansfor securing each step to the stringer comprise a plurality of hook bolts 17 which connect each tread 16 withthe stringers. Each of these bolts is curved or arcu'ate and preferably two of'such bolts extend through the stringer below one end of each tread, and pass upwardly through the tread. These bolts may be threaded at both ends and provided with nuts, or the same may be provided with heads, which may be counter sunk into the stringer, as shown at the left of Fig. 3' so as to provide a smooth surface 'on the outer side thereof. Thetreads are supported by a plurality of quarterround bearing bars 18, each'of which extends longi tudinally oft-the stairway and is confined between the hook-bolts, tread and stringers, the flat faces thereof engaging the under side of the tread and the inner face of the stringer, and the round face thereof engaging the inner sides of the'arcuate'hookbolts. p

Itis obvious that after'the parts of the stairway are loosely assembled, the hookbolts' may be drawn tight, which forces the tread down upon the quarter round bearing bar 18 and thereby securely fastens the ends of each tread to the stringers. The tread is also supported"throughoutitsentire width by the bearing bar, 'and is therefore very This arrangement of hook bolts in combinationlwith the "bearing bar also serves to render the parts self aligning, since the tight when the stairway is being erected.

loo

To guide the treads and risers into proper position with relationto the spacing of the steps, and also to solidly interlock the outer corners ofeach riser and tread without using bolts or other fastenings for this purpose, a nosing19 is provided on theupper end'of the riser 15, which extends over and around a reversely formed hook portion on the front end-of the tread. The nosing is comof the tread, and having an inclination corv responding to the inclined base portion 21 of the nosing, and. an upper flange extending obliquely upwardly and rearwardly from the upper end thereof. Thisfiange is ofsuch a length as to firmly engage the inher side of the rear. portion of the nosing the step to inaccuracies, and after it is in.

bolted in place.

and is preferably suflici-ent-ly yielding to adapt itself to the nosing as the successive steps are assembled. In assembling the stairway, assuming the stairway to be built from the top down, the step to be fastened in place is elevated and its nosing locked under the flange 25of the next higher step which has previously been secured. The step is then swung down, the nosing interlocks with the reversely formed portion of the fixed tread, and the same may then be The inclined engagement between the nosing and the tread permits the same to be moved up and down to adapt position holds the same until bolted. The tread is then filled with cement 26, which is poured so as to be flush with the tread 22 of the nosing and extends to the riser at the rear end of the tread. After the cement hardens, the nosing is, of course, embedded and rendered solid. i

In the modified form of my invention shown in Figs. 9-13 the arcuate body portions of the hook bolts 17 arearranged above the tread and are embeddedwithin the cement. In this construction one hook bolt is arranged at the center of the tread 1.6 at

each end thereof; one extends through the lower end of the riser, and one is arranged at each end of the nosing, which last mentioned bolt penetrates both the upper end of the riser and the front end of the tread. This form permits the stairs to be moved a considerable extent both vertically and hori zontally, bytight-ening the several bolts to a greater or less extent, and therefore enables the stairway to. be readily. adjusted and properly. assembled without cutting or re.- drilling inaccurately made parts. In this construction short sections of quarter round bars 27 may also be placed under the hook bolts 17, the function of the bars being to serve as an abutment and guide forthe step and bolts, the upward movement of the tread, and the lateral movement of the riser being limited thereby when the bolts are drawi'rtight. i

Inasmuch as in this form the parts of the tread and riser forming the nosing of the step are bolted together, the interlocking nosing shown as the preferred construction need not beemployed, but any well known and approved form of nosing construction may be used. As shown in Figs. 7, 8, 9 and 12, the riser may be flat and the tread formed to provide a vertical flange 28 at its front end, the hook bolt being headed to give the nosing a finished appearance, or as shownin Fig. 13, thehead of the bolt may be counter sunk, and thestep provided with a: tread plate 29 cemented to. the upperSide of the trcadand having a nosing 5O overhanging the nosing of the step. i

This invention, as shown inFig. 14 may also beused in connection with an all; steel stairway, the hook bolt 17 extending upwardly through a checkered tread 31 and having a round headat its upper end. The

nosing 32 in this construction preferably overlaps the upper end of the'riser and is secured thereto bya bolt 33 passing therethrough. 7 V i i As a whole, this invention provides a very simple, inexpensive and easily assembled stair. The stairwayis also very strong and rigid and of attractive appearance. Q

I claim as my invention: y

.1. In a stairway, a stringer, a step extending laterally outward from said stringer, said step comprising a riser section and tread fastening said tread to said stringer comprising hook bolts arranged above said tread and embedded in said cement, the ends of said hook bolts extending through said stringer and said tread.

2. In a stairway, a stringer, a stairmeni-M ber projecting perpendicularly outward from said stringer, said stair member being provided at a pointspaced from said string er with a hole, and said stringer being provided at a point spaced fromlsaid'stair memher with a hole, and means for fastening said stair 'memberto said stringer comprising a threaded hook bolt penetrating said holes and a nut arranged on said hook bolt and adapted todraw said stair member toward said stringer.

33. In a stairway,

provided at a point spaced from said string;

' or with ahole, and said stringer being provided with a corresponding hole spaced a substantially equal distance from. said stair.

member, and means for fastening said stair member to said stringer comprising an arcuate hook bolt disposedIperpendicularly to said stair member and stringer andpassing astringer, a stairmem ber pro ec t1ng. perpendicularly outward from said stringer, saidstairmember being" Joe section, a cement filler arranged on the upper side of said tread section, and means tor,

ies

through said holes, and a nut on said hook bolt adapted to draw said stairmember toard said stringer. 7

t. In a stairwa a stringer, a stair member projecting perpendicularly outward from said stringer, said stair member being provided at a point spaced from said stringer with a hole and said stringer being provided at a point spaced fromsaid stair member with another hole, and means for fastening said stair member to saidstringer comprising an arcuatehook member penetrating said holes, an integrally formed head at one end of said hook boltand a nut at the other end of said arcuate hook bolt and adapted to draw said stair member toward said stringer.

5. In a stairway, a stringer, a stair member projecting perpendicularly outward from said stringer, said stair member being provided at a point spaced from said stringer with a hole and said stringer being provided at a point spaced from said stair member with a second hole, both of said holes being substantially equidistant from the point of juncture of said stair member and stringer, and means for securing said stair member 6. In a stairway, a stringer, a stair member projecting perpendicularly outward from said stringer, said stairmember being provided ata point spaced from said stringer with a hole and said stringer being provided at a point spaced from said stair member with a second hole, both of said holes being substantially equidistant from the point of juncture of said stair member and stringer, and means for securing said stair member to said string-er.comprising ,an arcuate hook r 45 bolt penetrating said holes, a nut arranged on said hook bolt and adapted to drawsaid stair member toward said stringer, and a quarter round bar arranged between said stringer, stair member and arcuate hook bolt. y

In testimony whereof I hereby aflix my signature.

LUnwie w. NORBERG! 

